1. Field of the Invention
The present invention relates generally to the field of electric machines, and more particularly to a three-phase connector for an electric vehicle drivetrain.
2. Background of the Invention
Phase connectors are connectors which carry current, for example, from the internally gated bipolar transistors (IGBT's) of an inverter to an electric motor. The IGBT is the power transistor in the inverter and generates the sine wave for the three-phase current. It is not possible to simply thread the wires for the three phases through an opening in the electric motor housing because the current carried through the phase connections is very high, such as 350-400 amps. In carrying the three-phase current from the IGBT of the inverter to a three-phase induction motor, the three phases must remain isolated, and it is necessary to have some kind of connector which isolates the phases from each other.
Previously, three separate connectors were used to carry the three-phase current to the electric motor. Fig. shows a cross-sectional view of such a prior art separate phase connector 2. All three separate connectors were required to isolate the electric current from the motor housing as it passed through from the inverter. With separate phase connectors, each of the three individual connectors carries a separate phase current through a separate opening in the motor casing and is fastened with a separate set of fasteners. Thus, separate phase connectors require many different parts and must each be individually bolted to the housings with separate holes drilled for each connector. The resulting package was large, costly, and required significant effort to assemble.